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Comet Stepping Stones
| Title |
Comet Stepping Stones |
| Description |
This image from NASA's Spitzer Space Telescope shows three of the many fragments making up Comet 73P/Schwassman-Wachmann 3. The infrared picture also provides the best look yet at the crumbling comet's trail of debris, seen here as a bridge connecting the larger fragments. The comet circles around our sun every 5.4 years. In 1995, it splintered apart into four pieces, labeled A through D, with C being the biggest. Since then, the comet has continued to fracture into dozens of additional pieces. This image is centered about midway between fragments C and B, fragment G can be seen in the upper right corner. The comet's trail is made of dust, pebbles and rocks left in the comet's wake during its numerous journeys around the sun. Such debris can become the stuff of spectacular meteor showers on Earth. This image was taken on April 1, 2006, by Spitzer's multi-band imaging photometer using the 24-micron wavelength channel. |
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NASA Connect - ETPTAS - Sun
In Path of Totality: Measuri
2/17/10
| Description |
In Path of Totality: Measuring Angular Size and Distance, students learn about the natural phenomena that create a total eclipse. Students also explore the history, mythology, science, and math that relate to these amazing events. NASA scientists and engineers introduce a satellite where scientists make artificial eclipses in order to learn more about the Sun«ÉŸs corona. Using hands-on lessons, web-based activities and simple tools, students will measure the angular size and predict the angular distance of objects in the sky. |
| Date |
2/17/10 |
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Saturn and Earth Ready for C
| Description |
SOHO images show Saturn on the left moving toward the Sun |
| Full Description |
Saturn has a date to keep with Earth and the Sun. Since the Cassini spacecraft is orbiting Saturn, it's tagging along. Once a year Saturn and Earth find themselves almost directly opposite each other with the Sun in between, an event called conjunction. This year, conjunction will occur on Aug. 7. NASA's Solar and Heliospheric Observatory, known as SOHO (http://sohowww.nascom.nasa.gov/), keeps close watch on the Sun. SOHO images show Saturn on the left moving toward the Sun, which is shielded from view but represented by a white circle in the image center. When Saturn emerges from conjunction, it will appear in SOHO images heading toward the right and away from Sun. As Earth and Saturn play peekaboo with each other, radio communications with Cassini get very noisy, so most of Cassini's science operations are temporarily suspended. "We'll still be in constant communication," says David Doody, Cassini flight operations lead, "and we'll see the quality degrading as it nears the Sun. The last high-rate science data playback, at 14,220 bits per second, will occur Aug. 4, after which Cassini switches to low-rate telemetry downlink, at 1896 bps." During conjunction, the mission switches gears. "Finally, a break," says Doody. "We know the spacecraft is safe, especially since it won't be doing lots of commanded science activities, instead just staring at Earth with its high gain antenna. We'll be carrying out radio science studies of the solar corona, using carrier signals coming down from Cassini to study the sun's extended, super-hot atmosphere. Meanwhile, the spacecraft team's radio communications engineers will watch how many out of 100 test commands sent each day are received aboard the spacecraft with the noisy Sun in the way.""We'll also be using this low-activity period to conduct an operational readiness test, realistic training using contrived problems, for many of the new members of the flight team," adds Doody. Cassini will resume returning high-rate science data on Aug. 10, when it is well past the Sun. Note for sky watchers: The first time that Saturn will be visible again to the unaided eye from here on Earth will be about two weeks after conjunction. On the morning of Aug. 20, Saturn will rise in the east an hour before the sun does. Early birds in the United States will be able to spot swift Mercury one degree above Saturn. The next morning, they can spot Mercury one degree to the lower left of the planet. On Aug. 26 and 27 Saturn pairs with much brighter Venus. To see the latest image from SOHO click here. |
| Date |
August 3, 2006 |
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August 2006: View of the Pla
| Description |
August 2006: View of the Planets |
| Full Description |
Just before the eastern sky brightens with sunrise, three planets and the waning crescent moon join the starry twilight tapestry. Then, as the bright stars of Gemini and Orion fade with oncoming dawn, the planets rise and shine. About 45 minutes before sunrise on Aug. 20 to 22 the planets Venus, Mercury and Saturn dance on the ecliptic -- the plane of Earth's orbit and the imaginary line tracing it in the sky. The sun, moon and planets appear to move along this line. Venus, rising an hour and a half before sunrise, is the easiest to see in the morning sky. Two hundred forty-one million kilometers (150 million miles) distant, Venus is Earth-sized. Mercury, at a distance of 183 million kilometers (114 million miles), is the fastest and smallest of the inner planets and appears brighter than the more distant Saturn. Saturn, 1,517 million kilometers (943 million miles) distant, was at conjunction with the sun just two weeks ago and now rises nearly an hour before sunrise. On Aug. 26 and 27, Saturn pairs with much brighter Venus at dawn. What other planets can we see in late August? Mars sets 45 minutes after sunset by month's end but is lost from view in the twilight, while brilliant Jupiter remains prominent as the only planet visible for a few hours during the late August evenings. Credit: NASA/JPL |
| Date |
August 18, 2006 |
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Pale Blue Orb (1)
| Description |
Pale Blue Orb |
| Full Description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image (see inset), with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus, for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is 129 kilometers (80 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov ., The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
September 19, 2006 |
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In Saturn's Shadow (Color-ex
| Description |
In Saturn's Shadow (Color-exagerated view) |
| Full Description |
+ Original version + Image with labels With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the, images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
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Looking Saturn in the Eye
| Description |
Looking Saturn in the Eye |
| Full Description |
+ View Movie Cassini stares deep into the swirling hurricane-like vortex at Saturn's south pole, where the vertical structure of the clouds is highlighted by shadows. Such a storm, with a well-developed eye ringed by towering clouds, is a phenomenon never before seen on another planet. This 14-frame movie shows a swirling cloud mass centered on the south pole, around which winds blow at 550 kilometers (350 miles) per hour. The frames have been aligned to make the planet appear stationary, while the sun appears to revolve about the pole in a counterclockwise direction. The clouds inside the dark, inner circle are lower than the surrounding clouds, which cast a shadow that follows the sun. At the beginning of the movie, the sun illuminates directly from the top, and by the end it illuminates from the left. The width of the shadow and the height of the sun above the local horizon yield a crude estimate of the height of the surrounding clouds relative to the clouds in the center. The shadow-casting clouds tower 30 to 75 kilometers (20 to 45 miles) above those in the center. This is two to five times greater than the tallest terrestrial thunderstorms and two to five times the height of clouds surrounding the eye of a terrestrial hurricane. Such a height difference arises because Saturn's hydrogen-helium atmosphere is less dense at comparable pressures than Earth's atmosphere, and is therefore more distended in the vertical dimension. The south polar storm, which displays two spiral arms of clouds extending from the central ring and spans the dark area inside a thick, brighter ring of clouds, is approximately 8,000 kilometers (5,000 miles) across, which is considerably larger than a terrestrial hurricane. Eye-wall clouds are a distinguishing feature of hurricanes on Earth. They form where moist air flows inward across the ocean's surface, rising vertically and releasing a load of precipitation around an interior circular region of descending air, which is the eye itself. Though it is uncertain whether moist convection is driving this storm, as is the case with Earthly hurricanes, the dark 'eye' at the pole, the eye-wall clouds and the spiral arms together indicate a hurricane-like system. The distinctive eye-wall clouds especially have not been seen on any planet beyond Earth. Even Jupiter's Great Red Spot, much larger than Saturn's polar storm, has no eye, no eye-wall, and is relatively calm at the center. This giant Saturnian storm is apparently different from hurricanes on Earth because it is locked to the pole, does not drift around like terrestrial hurricanes and because it does not form over liquid water oceans. The images were acquired over a period of three hours on Oct. 11, 2006, when Cassini was approximately 340,000 kilometers (210,000 miles) from Saturn. Image scale is about 17 kilometers (11 miles) per pixel. The images were taken with the wide-angle camera using a spectral filter sensitive to wavelengths of infrared light, centered at 752 nanometers. All frames have been contrast enhanced using digital image processing techniques. The unprocessed images show an oblique view toward the pole, and have been reprojected to show the planet from a perspective directly over the south pole. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
November 9, 2006 |
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View Out the Window
| Description |
View Out the Window |
| Full Description |
The Cassini spacecraft returns a grand and unique vista of Saturn's horizon, reminiscent of the views of our own planet from Earth orbit. Similar to the view from Swirling With Shadows, the high clouds in the lower part of the scene cast shadows toward the bottom of the image. This view was obtained from about 44 degrees above the ringplane. The image was taken with the Cassini spacecraft narrow-angle camera using a spectral filter sensitive to wavelengths of infrared light centered at 938 nanometers on Oct. 30, 2006. Cassini was then at a distance of approximately 1.4 million kilometers (900,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 150 degrees. Image scale is 8 kilometers (5 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
December 4, 2006 |
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Greetings from Saturn
| Description |
Greetings from Saturn |
| Full Description |
Only Cassini could provide this enchanting, natural color view of crescent Saturn, which gazes down onto the unlit side of the planet's spectacular rings. The robotic ship plies the peaceful black seas around the ringed giant, searching for answers to the many questions posed by the inquisitive minds of Earth. This view looks toward the unlit side of the rings from about 19 degrees above the ringplane. The view of Saturn is through the dark rings at bottom, the rings cast shadows onto the northern hemisphere at top. Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken with the Cassini spacecraft wide-angle camera on Nov. 4, 2006 at a distance of approximately 1.7 million kilometers (1 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 162 degrees. Image scale is 97 kilometers (61 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
December 25, 2006 |
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Moons in the Night
| Description |
Moons in the Night |
| Full Description |
Sunlight makes visible the faint band called the E ring as two moons meet in the sky. Enceladus (505 kilometers, or 314 miles across) and Tethys (1,071 kilometers, or 665 miles across) appear close together in the sky in this image, but in reality, Tethys was more than 260,000 kilometers (162,000 miles) farther from the Cassini spacecraft -- greater than half the distance from Earth to the Moon. Enceladus is easy to identify by the brilliant plume of ice erupting from its south pole. Although this perspective views the night sides of both moons, the Sun is not the only source of illumination in the Saturn system. Tethys is at a fuller phase with respect to Saturn, and thus its "night side" is more fully lit than that of Enceladus. The view was acquired from a Sun-Enceladus-spacecraft, or phase, angle of 163 degrees, a viewing geometry in which the microscopic ice particles in its plume brighten substantially. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 6, 2006 at a distance of approximately 3.9 million kilometers (2.4 million miles) from Enceladus and 4.2 million kilometers (2.6 million miles) from Tethys. Image scale is 23 kilometers (14 miles) per pixel on Enceladus and 25 kilometers (16 miles) on Tethys. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
April 16, 2007 |
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Mimas...and Titan Beyond
| Description |
Mimas...and Titan Beyond |
| Full Description |
Titan, Saturn's largest moon, and Mimas, closer but much smaller on the right, are seen together in this view from Cassini. Titan's gravity is weaker than Earth's, so the moon's atmosphere is quite extended -- a quality hinted at in this view. Part of Mimas' dark side is illuminated by reflected light from nearby Saturn. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2005, at a distance of approximately 3.6 million kilometers (2.2 million miles) from Titan (5,150 kilometers, or 3,200 miles across) and 2.5 million kilometers (1.6 million miles) from Mimas (397 kilometers, or 247 miles across). Both moons are seen at a Sun-moon-spacecraft angle, or phase angle, of 110 degrees. The image scale is 22 kilometers (14 miles) per pixel on Titan and 15 kilometers (9 miles) per pixel on Mimas. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . *Credit:* NASA/JPL/Space Science Institute |
| Date |
January 3, 2006 |
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Ringside Seats for Saturn
| Description |
Saturn reaches opposition -- the closest it comes to Earth -- on Jan. 27, 2006. |
| Full Description |
Saturn reaches opposition -- the closest it comes to Earth -- on Jan. 27, 2006. On this date, golden Saturn rises in the east just as the sun sets in the west. It will be visible all night long. A planet is in opposition when it is on one side of Earth directly opposite the Sun on the other side. As a result, it appears fully illuminated by the Sun. Opposition brings Saturn a mere 1,215 million kilometers (755 million miles) from Earth. January through June are the best months to view Saturn this year. In late January, if you wait a few hours after sunset you'll be rewarded with better views through the telescope. Even the smallest telescope will reveal a golden orb surrounded by Saturn's amazing rings. You may even spot one or more of Saturn's moons orbiting the planet. For more Saturn viewing information, visit the Saturn Observation Campaign viewing page. |
| Date |
January 24, 2006 |
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The Record of Rhea
| Description |
The Record of Rhea |
| Full Description |
Cassini looks down upon Rhea, whose cratered surface was already ancient before any complex life developed on Earth. The terrain seen here has probably changed little in the past billion years. This view shows terrain on the Saturn-facing hemisphere of Rhea (1,528 kilometers, or 949 miles across). North is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 21, 2006 at a distance of approximately 94,000 kilometers (59,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase, angle of 109 degrees. Image scale is 558 meters (1,832 feet) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit:NASA/JPL/Space Science Institute |
| Date |
May 8, 2006 |
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Ring of Light
| Description |
Ring of Light |
| Full Description |
Dazzling Titan glows with a 360-degree sunset as light scatters through its very extended atmosphere. Some structure is visible in the hazes of the northern polar hood. To the left is Janus (181 kilometers, or 113 miles across), far off on the opposite side of the ringplane. The rings show their unlit side to Cassini, as the spacecraft viewed them from slightly above the ringplane. A world with strikingly Earth-like physical processes, frigid Titan is Saturn's largest natural satellite, at 5,150 kilometers (3,200 miles) across. Titan's image is saturated at the 5 o'clock position. The view was acquired in visible light with the Cassini spacecraft narrow-angle camera on June 2, 2006 at a distance of approximately 2.3 million kilometers (1.5 million miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 163 degrees. Cassini was 3.7 million kilometers (2.3 million miles) from Janus. Image scale is 14 kilometers (9 miles) per pixel on Titan and 22 kilometers (14 miles) on Janus. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
June 30, 2006 |
|
In Saturn's Shadow (with lab
| Description |
In Saturn's Shadow (with labels) |
| Full Description |
+ Original version + Color-exagerated version With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints, only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color. The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See The Janus/Epimetheus Ring and Moon-Made Rings for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge. Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See Pale Blue Orb for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when, the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
October 11, 2006 |
|
Psychedelic Saturn
| Description |
Psychedelic Saturn |
| Full Description |
Streamers, swirls and vortices roll across the dynamic face of Saturn. Unlike Earth, where most of the weather is driven by the Sun, Saturn's storms and circulation are driven in part by internal heating. Amazingly, the planet is still contracting (ever so slightly) from its formation, more than 4.5 billion years ago. This gravitational contraction liberates energy in the form of heat. The image was taken in polarized infrared light with the Cassini spacecraft narrow-angle camera on March 7, 2006, at a distance of approximately 2.9 million kilometers (1.8 million miles) from Saturn. The image scale is 17 kilometers (10 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/Space Science Institute |
| Date |
April 12, 2006 |
|
Looking Saturn in the Eye
| title |
Looking Saturn in the Eye |
| date |
11.09.2006 |
| description |
Cassini stares deep into the swirling hurricane-like vortex at Saturn's south pole, where the vertical structure of the clouds is highlighted by shadows. Such a storm, with a well-developed eye ringed by towering clouds, is a phenomenon never before seen on another planet. This 14-frame movie shows a swirling cloud mass centered on the south pole, around which winds blow at 550 kilometers (350 miles) per hour. The frames have been aligned to make the planet appear stationary, while the sun appears to revolve about the pole in a counterclockwise direction. The clouds inside the dark, inner circle are lower than the surrounding clouds, which cast a shadow that follows the sun. At the beginning of the movie, the sun illuminates directly from the top, and by the end it illuminates from the left. The width of the shadow and the height of the sun above the local horizon yield a crude estimate of the height of the surrounding clouds relative to the clouds in the center. The shadow-casting clouds tower 30 to 75 kilometers (20 to 45 miles) above those in the center. This is two to five times greater than the tallest terrestrial thunderstorms and two to five times the height of clouds surrounding the eye of a terrestrial hurricane. Such a height difference arises because Saturn's hydrogen-helium atmosphere is less dense at comparable pressures than Earth's atmosphere, and is therefore more distended in the vertical dimension. The south polar storm, which displays two spiral arms of clouds extending from the central ring and spans the dark area inside a thick, brighter ring of clouds, is approximately 8,000 kilometers (5,000 miles) across, which is considerably larger than a terrestrial hurricane. Eye-wall clouds are a distinguishing feature of hurricanes on Earth. They form where moist air flows inward across the ocean's surface, rising vertically and releasing a load of precipitation around an interior circular region of descending air, which is the eye itself. Though it is uncertain whether moist convection is driving this storm, as is the case with Earthly hurricanes, the dark 'eye' at the pole, the eye-wall clouds and the spiral arms together indicate a hurricane-like system. The distinctive eye-wall clouds especially have not been seen on any planet beyond Earth. Even Jupiter's Great Red Spot, much larger than Saturn's polar storm, has no eye, no eye-wall, and is relatively calm at the center. This giant Saturnian storm is apparently different from hurricanes on Earth because it is locked to the pole, does not drift around like terrestrial hurricanes and because it does not form over liquid water oceans. The images were acquired over a period of three hours on Oct. 11, 2006, when Cassini was approximately 340,000 kilometers (210,000 miles) from Saturn. Image scale is about 17 kilometers (11 miles) per pixel. The images were taken with the wide-angle camera using a spectral filter sensitive to wavelengths of infrared light centered at 752, nanometers. All frames have been contrast enhanced using digital image processing techniques. The unprocessed images show an oblique view toward the pole, and have been reprojected to show the planet from a perspective directly over the south pole. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . |
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The Little Red Spot: Closest
| title |
The Little Red Spot: Closest View Yet |
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02.26.2007 |
| description |
This is a mosaic of three New Horizons images of Jupiter's Little Red Spot, taken with the spacecraft's Long Range Reconnaissance Imager (LORRI) camera at 17:41 Universal Time on February 26 from a range of 3.5 million kilometers (2.1 million miles). The image scale is 17 kilometers (11 miles) per pixel, and the area covered measures 33,000 kilometers (20,000 miles) from top to bottom, two and one-half times the diameter of Earth. The Little Red Spot, a smaller cousin of the famous Great Red Spot, formed in the past decade from the merger of three smaller Jovian storms, and is now the second-largest storm on Jupiter. About a year ago its color, formerly white, changed to a reddish shade similar to the Great Red Spot, perhaps because it is now powerful enough to dredge up reddish material from deeper inside Jupiter. These are the most detailed images ever taken of the Little Red Spot since its formation, and will be combined with even sharper images taken by New Horizons 10 hours later to map circulation patterns around and within the storm. LORRI took the images as the Sun was about to set on the Little Red Spot. The LORRI camera was designed to look at Pluto, where sunlight is much fainter than it is at Jupiter, so the images would have been overexposed if LORRI had looked at the storm when it was illuminated by the noonday Sun. The dim evening illumination helped the LORRI camera obtain well-exposed images. The New Horizons team used predictions made by amateur astronomers in 2006, based on their observations of the motion of the Little Red Spot with backyard telescopes, to help them accurately point LORRI at the storm. These are among a handful of Jupiter system images already returned by New Horizons during its close approach to Jupiter. Most of the data being gathered by the spacecraft are stored onboard and will be downlinked to Earth during March and April 2007. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
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Pale Blue Orb (2)
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Pale Blue Orb (2) |
| date |
09.15.2006 |
| description |
Not since NASA's Voyager 1 spacecraft saw our home as a pale blue dot from beyond the orbit of Neptune has Earth been imaged in color from the outer solar system. Now, Cassini casts powerful eyes on our home planet, and captures Earth, a pale blue orb -- and a faint suggestion of our moon -- among the glories of the Saturn system. Earth is captured here in a natural color portrait made possible by the passing of Saturn directly in front of the sun from Cassini's point of view. At the distance of Saturn's orbit, Earth is too narrowly separated from the sun for the spacecraft to safely point its cameras and other instruments toward its birthplace without protection from the sun's glare. The Earth-and-moon system is visible as a bright blue point on the right side of the image above center. Here, Cassini is looking down on the Atlantic Ocean and the western coast of north Africa. The phase angle of Earth, seen from Cassini is about 30 degrees. A magnified view of the image taken through the clear filter (monochrome) shows the moon as a dim protrusion to the upper left of Earth. Seen from the outer solar system through Cassini's cameras, the entire expanse of direct human experience, so far, is nothing more than a few pixels across. Earth no longer holds the distinction of being our solar system's only "water world," as several other bodies suggest the possibility that they too harbor liquid water beneath their surfaces. The Saturnian moon, Enceladus, is among them, and is also captured on the left in this image, with its plume of water ice particles and swathed in the blue E ring which it creates. Delicate fingers of material extend from the active moon into the E ring. See Ghostly Fingers of Enceladus [ http://saturn.jpl.nasa.gov/multimedia/images/image-details.cfm?imageID=2276 ], for a more detailed view of these newly-revealed features. The narrow tenuous G ring and the main rings are seen at the right. The view looks down from about 15 degrees above the un-illuminated side of the rings. Images taken using red, green and blue spectral filters were combined to create this view. The image was taken by the Cassini spacecraft wide-angle camera on Sept. 15, 2006, at a distance of approximately 2.1 million kilometers (1.3 million miles) from Saturn and at a sun-Saturn-spacecraft angle of almost 179 degrees. Image scale is approximately 250 kilometers (155 miles) per pixel. At this time, Cassini was nearly 1.5 billion kilometers (930 million miles) from Earth. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For, more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] . The Cassini imaging team homepage is at http://ciclops.org [ http://ciclops.org ] . Credit: NASA/JPL/Space Science Institute |
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New Horizons Tracks an Aster
| title |
New Horizons Tracks an Asteroid |
| date |
06.12.2006 |
| description |
The two "spots" in this image are a composite of two images of asteroid 2002 JF56 taken on June 11 and June 12, 2006, with the Multispectral Visible Imaging Camera (MVIC) component of the New Horizons Ralph imager. In the bottom image, taken when the asteroid was about 3.36 million kilometers (2.1 million miles) away from the spacecraft, 2002 JF56 appears like a dim star. At top, taken at a distance of about 1.34 million kilometers (833,000 miles), the object is more than a factor of six brighter. The best current, estimated diameter of the asteroid is approximately 2.5 kilometers. The asteroid observation was a chance for the New Horizons team to test the spacecraft's ability to track a rapidly moving object. On June 13 New Horizons came to within about 102,000 kilometers of the small asteroid, when the spacecraft was nearly 368 million kilometers (228 million miles) from the Sun and about 273 million kilometers (170 million miles) from Earth. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
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Hubble Space Telescope Compl
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Hubble Space Telescope Completes Eighth Year Of Exploration |
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Hubble Panoramic View of Ori
| Title |
Hubble Panoramic View of Orion Nebula Reveals Thousands of Stars |
| General Information |
What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. In one of the most detailed astronomical images ever produced, NASA's Hubble Space Telescope captured an unprecedented look at the Orion Nebula. This turbulent star formation region is one of astronomy's most WATCH: HubbleMinute Video Hubble Minute: Hubble Snaps the Clearest View of the Orion Nebula Hubble Minute: Hubble Snaps the Clearest View of the Orion Nebula [ http://hubblesite.org/newscenter/archive/releases/2006/01/video/a/ ] READ: Junior version of this article Amazing Space Learn about this story in the Star Witness, a science newspaper available on our sister site, Amazing Space. [ http://amazing-space.stsci.edu/news/archive/2006/01/ ] dramatic and photogenic celestial objects. More than 3,000 stars of various sizes appear in this image. Some of them have never been seen in visible light. These stars reside in a dramatic dust-and-gas landscape of plateaus, mountains, and valleys that are reminiscent of the Grand Canyon. The Orion Nebula is a picture book of star formation, from the massive, young stars that are shaping the nebula to the pillars of dense gas that may be the homes of budding stars. Read more: * NASA Press Release [ http://hubblesite.org/newscenter/archive/releases/2006/01/text/ ] * The Full Story [ http://hubblesite.org/newscenter/archive/releases/2006/01/full/ ] |
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Hubble Confirms New Moons of
| Title |
Hubble Confirms New Moons of Pluto |
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Astronomers Find Smallest Ex
| Title |
Astronomers Find Smallest Extrasolar Planet Yet Around Normal Star |
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Hubble Provides Spectacular
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Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
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Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
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Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
| Title |
Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
| Title |
Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
| Title |
Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Provides Spectacular
| Title |
Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble Snaps Baby Pictures o
| Title |
Hubble Snaps Baby Pictures of Jupiter's "Red Spot Jr. |
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Astronomers Use Innovative T
| Title |
Astronomers Use Innovative Technique to Find Extrasolar Planet |
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Hubble Observations Confirm
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Hubble Observations Confirm that Planets Form from Disks Around Stars |
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Hubble Finds Extrasolar Plan
| Title |
Hubble Finds Extrasolar Planets Far Across Galaxy |
| General Information |
What is a NASA Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a NASA Science Update (NSU), broadcast on NASA television. The NSU includes a question and answer session with members of the media. NASA's Hubble Space Telescope has discovered 16 extrasolar planet candidates orbiting a variety of distant stars in the central region of our Milky Way galaxy. The planet bonanza was uncovered during a Hubble survey, called the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS). Hubble looked farther than has ever successfully been searched for extrasolar planets. Hubble peered at 180,000 stars in the crowded central bulge of our galaxy 26,000 light-years away or one-quarter the diameter of the Milky Way's spiral disk. The results will appear in the Oct. 5 issue of the journal Nature. Read more: * NASA Press Release [ http://hubblesite.org/newscenter/archive/releases/2006/34/text/ ] |
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Hubble Captures a Rare Eclip
| Title |
Hubble Captures a Rare Eclipse on Uranus |
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The Carina Nebula: Star Birt
| Title |
The Carina Nebula: Star Birth in the Extreme |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. In celebration of the 17th anniversary of the launch and deployment of NASA's Hubble Space Telescope, a team of astronomers is releasing one of the largest panoramic images ever taken with Hubble's cameras. READ: Junior version of this article Amazing Space Learn about this story in the Star Witness, a science newspaper available on our sister site, Amazing Space. [ http://amazing-space.stsci.edu/news/archive/2007/02/ ] It is a 50-light-year-wide view of the central region of the Carina Nebula where a maelstrom of star birth —, and death —, is taking place. This image is a mosaic of the Carina Nebula assembled from 48 frames taken with Hubble's Advanced Camera for Surveys. The Hubble images were taken in the light of neutral hydrogen during March and July 2005. Color information was added with data taken in December 2001 and March 2003 at the Cerro Tololo Inter-American Observatory in Chile. Red corresponds to sulfur, green to hydrogen, and blue to oxygen emission. |
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Hubble Images of Asteroids H
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Hubble Images of Asteroids Help Astronomers Prepare for Spacecraft Visit |
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Astronomers Find Highly Elli
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Astronomers Find Highly Elliptical Disk Around Young Star |
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Hubble Zooms In on Heart of
| Title |
Hubble Zooms In on Heart of Mystery Comet |
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Dusty Planetary Disks Around
| Title |
Dusty Planetary Disks Around Two Nearby Stars Resemble Our Kuiper Belt |
| General Information |
What is a News Nugget? News Nuggets are bulletins from the world of astronomy. These two bright debris disks of ice and dust appear to be the equivalent of our own solar system's Kuiper Belt, a ring of icy rocks outside the orbit of Neptune and the source of short-period comets. The disks encircle the types of stars around which there could be habitable zones and planets for life to develop. The disks seem to have a central area cleared of debris, perhaps by planets. |
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Hubble Provides Spectacular
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Hubble Provides Spectacular Detail of a Comet's Breakup |
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Hubble's Latest Look at Plut
| Title |
Hubble's Latest Look at Pluto's Moons Supports a Common Birth |
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Astronomers Use Innovative T
| Title |
Astronomers Use Innovative Technique to Find Extrasolar Planet |
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Planet Or Failed Star? NASA'
| Title |
Planet Or Failed Star? NASA's Hubble Telescope Photographs One of Smallest Stellar Companions Ever Seen |
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Planet Or Failed Star? NASA'
| Title |
Planet Or Failed Star? NASA's Hubble Telescope Photographs One of Smallest Stellar Companions Ever Seen |
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Planet Or Failed Star? NASA'
| Title |
Planet Or Failed Star? NASA's Hubble Telescope Photographs One of Smallest Stellar Companions Ever Seen |
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Hubble Sees Faintest Stars i
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Hubble Sees Faintest Stars in a Globular Cluster |
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Hubble Captures a Rare Eclip
| Title |
Hubble Captures a Rare Eclipse on Uranus |
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Hubble's Latest Views of Lig
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Hubble's Latest Views of Light Echo from Star V838 Monocerotis |
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